package com.heima.kafka.sample;

import org.apache.kafka.clients.consumer.*;


import java.time.Duration;
import java.util.Collections;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerQuickStart {
    public static void main(String[] args) {
        //1.kafka配置信息
        Properties properties = new Properties();
        //kafka连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.190.168");
        //消费者组
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "group1");
        //消息key的反序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        //消息value的反序列化器
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        //消费者对象
        KafkaConsumer<String,String> consumer=new KafkaConsumer<String,String>(properties);
        //订阅主题
        consumer.subscribe(Collections.singletonList("kafka_topic"));
        //当前线程一直处于监听状态
        while (true){
            //获取消息
            //ofMillis表示多长时间(毫秒)拉取一次
            ConsumerRecords<String,String> consumerRecords=consumer.poll(Duration.ofMillis(10));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
            }
        }
    }
}
